1. Field of Invention
The invention relates to an electric connection box suitable to be mounted in, for example, a vehicle such as an automobile.
2. Description of Related Art
One form of an electric connection box provides a case composed of a casing part for a bus bar laminate and casing part for a wiring substrate. The bus bar laminate is formed by alternatingly laminating bus bars and insulation layers. A substrate connector making electrical connection with the bus bars is mounted on the wiring substrate. In assembly, the bus bars are received in the substrate casing part when the two casing parts are united, and the bus bars are connected with the substrate connector. It is required that the two casing parts are accurately positioned before combination so that the connection position of the bus bars coincides with the substrate connector. Accordingly, an electric connection box in which the two casing parts are joined when accurately positioned has been proposed. The electric connection box aligns the casing parts by bringing the wiring substrate casing part in contact with guide pieces formed on the upper face of the laminate casing part. However, in this box, bus bars are aligned with the substrate connector indirectly by positioning of the wiring substrate through its casing part. Therefore, there have been problems that deviation of the connection position of the bus bars with the connector occurs, and good connection cannot be achieved because of dimension tolerance of the respective casing parts, assembly error of the wiring substrate in its casing part, and the like.
U.S. Pat. No. 5,822,189 illustrates an electrical connection box, for automotive use, which also seeks to achieve good connection of a bus bar laminate and connectors of a wiring board. A lower casing contains a bus bar laminate having upwardly projecting tab terminals. Into this casing a circuit board is fitted, which carries on its edges connector housings which receive the tab terminals. In one embodiment, the connector housings are positioned by guide ribs of the lower casing, which also serve to ensure correct location of the connector housings on the circuit board. After fitting of the circuit board in this manner, an upper casing is fitted on the lower casing, pressing on the circuit board.
An object of the invention is to provide an electric connection box capable of satisfactorily connecting a bus bar laminate with a connector.
According to the invention, there is provided an electrical connection box including a first casing part and a second casing part connectable with the first casing part. A bus bar laminate, having at least one bus bar and at least one insulation layer laminated together, is mounted in the first casing part and has projecting terminals. A wiring substrate is mounted in the second casing part and has connectors carried thereon, adapted to engage and make connection to the projecting terminals of the bus bar laminate when the casing parts are connected. The first casing part and the wiring substrate have portions constituting mutually engageable guides which, during connection of the casing parts, directly establish mutual alignment of the first casing part and the wiring substrate before the connectors engage the projecting terminals.
In the invention, when the first casing part with the bus bar laminate is combined with the second casing part with the wiring substrate, the wiring substrate is directly positioned against the laminate casing part by the positioning procedure performed by the guides. The positioning is carried out before the tab terminals of the bus bars are inserted in the connectors of the wiring substrate. Accordingly, it is assured that the connection position of the bus bars coincides with the connectors without being influenced by dimensional tolerance or the like of the first casing part. Therefore, good connection between the bus bars and the connectors can be achieved.
Preferably, the mutually engageable guides include at least one guide projection on one of the first casing part and the wiring substrate, and at least one guide recess in the other of the first casing part and the wiring substrate. The first casing part preferably has a substrate-receiving recess bounded by a surrounding wall which receives the wiring substrate when the casing parts are connected together, the guide projection is a protrusion on the surrounding wall projecting inwardly to said substrate-receiving recess, and the guide recess is a notch in a peripheral region of the wiring substrate.
To support and locate the terminals of the bus bar laminate, preferably the first casing part has a portion overlying the bus bar laminate and directly engaging the projecting terminals so as to determine the position of the projecting terminals relative to said first casing part.
Preferably, each of the first casing part and the wiring substrate has a pair of the portions constituting mutually engageable guides, located respectively at opposite sides of the electrical connection box.
Typically the wiring substrate is a planar board carrying wiring and a plurality of electrical components.